1 /*
2 * Copyright (C) 2017 Joe Lawrence <joe.lawrence@redhat.com>
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version 2
7 * of the License, or (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, see <http://www.gnu.org/licenses/>.
16 */
17
18 /*
19 * livepatch-callbacks-busymod.c - (un)patching callbacks demo support module
20 *
21 *
22 * Purpose
23 * -------
24 *
25 * Simple module to demonstrate livepatch (un)patching callbacks.
26 *
27 *
28 * Usage
29 * -----
30 *
31 * This module is not intended to be standalone. See the "Usage"
32 * section of livepatch-callbacks-mod.c.
33 */
34
35 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
36
37 #include <linux/module.h>
38 #include <linux/kernel.h>
39 #include <linux/workqueue.h>
40 #include <linux/delay.h>
41
42 static int sleep_secs;
43 module_param(sleep_secs, int, 0644);
44 MODULE_PARM_DESC(sleep_secs, "sleep_secs (default=0)");
45
46 static void busymod_work_func(struct work_struct *work);
47 static DECLARE_DELAYED_WORK(work, busymod_work_func);
48
busymod_work_func(struct work_struct * work)49 static void busymod_work_func(struct work_struct *work)
50 {
51 pr_info("%s, sleeping %d seconds ...\n", __func__, sleep_secs);
52 msleep(sleep_secs * 1000);
53 pr_info("%s exit\n", __func__);
54 }
55
livepatch_callbacks_mod_init(void)56 static int livepatch_callbacks_mod_init(void)
57 {
58 pr_info("%s\n", __func__);
59 schedule_delayed_work(&work,
60 msecs_to_jiffies(1000 * 0));
61 return 0;
62 }
63
livepatch_callbacks_mod_exit(void)64 static void livepatch_callbacks_mod_exit(void)
65 {
66 cancel_delayed_work_sync(&work);
67 pr_info("%s\n", __func__);
68 }
69
70 module_init(livepatch_callbacks_mod_init);
71 module_exit(livepatch_callbacks_mod_exit);
72 MODULE_LICENSE("GPL");
73
